Related papers: The electromagnetic effects in $K_{e4}$ decay
For the Nbar N system, the one-pion-exchange (OPE) interaction gives the largest attractive force for Nbar N with isospin I=0 and spin S=0, while a near threshold enhancement was observed for pbar p with I=0 and S=0 in J/psi -> gamma pbar p…
We study possible so far unaccounted isospin breaking effects in the relation between the pion form factor as determined in e^+e^- experiments and the corresponding quantity obtained after accounting for known isospin breaking effects by an…
We construct the complete effective chiral pion-nucleon Lagrangian in the presence of virtual photons to one loop. As an application, we consider strong and electromagnetic isospin violation for scattering of neutral pions off nucleons. We…
The anomaly (cusp) in the mass spectrum of two neutral pions from the three-pion decays of charged kaon has been observed in the NA48/2 experiment. Using the recently developed interpretation of this effect in terms of Chiral Perturbative…
The scattering of a nonrelativistic electron on a narrow solenoid of finite length is considered. In this case, the magnetic field outside the solenoid is not zero. Using the eikonal approximation, the differential and total cross sections…
Electromagnetic effects in the leptonic decay rates $\pi^+ \to \mu^+ \nu$ and $K^+ \to \mu^+ \nu$ are evaluated for the first time on the lattice. Following a method recently proposed in Ref. [1] the emission of virtual photons at leading…
We relate the asymmetries in the charged pions energy in the decay into $\pi^+\pi^-\pi^0$ of $K_L$ and of the tagged neutral kaons. The former asymmetry is a given combination of $\Re(\epsilon)$, $\Im(\epsilon)$, and $|\epsilon'|$.…
We evaluate energy levels of the K-pi system in the K* channel in finite volume using chiral unitary theory. We use these energy levels to obtain K-pi phase shifts, and then obtain the K* mass and its decay width. We investigate their…
We use the framework of effective field theories to discuss the determination of the S-wave \pi N scattering lengths from the recent high-precision measurements of pionic deuterium observables. The theoretical analysis proceeds in several…
Using a large sample of charm semileptonic decays collected by the FOCUS photoproduction experiment at Fermilab, we present evidence for a small, even spin K- \pi+ amplitude that interferes with the dominant K*0 component in the K-pi+ mu-…
An isospin analysis of $B\to\pi\pi$ decays yields $\sin 2\alpha$, where $\alpha$ is the usual CKM angle $\alpha\equiv arg [-V_{td}V_{tb}^\ast /(V_{ud}V_{ub}^\ast)]$, without hadronic uncertainty if isospin is a perfect symmetry. Isospin,…
We calculate the isospin symmetry violating effects to the reactions $pp\rightarrow d\pi ^+$ and $np\rightarrow d\pi ^0$ arising from the different hadron masses and from the Coulomb interaction between the positive pion and the deuteron.…
We calculate the leading isospin conserving few-nucleon contributions to pion scattering on $^2$H, $^3$He, and $^4$He. We demonstrate that the strong contributions to the pion-nucleus scattering lengths can be controlled theoretically to an…
The problem of the final state interaction in quasi-elastic $(e,e')$ scattering at large $Q^2$, is investigated by exploiting the idea that the ejected nucleon needs a finite amount of time to assume its asymptotic form. It is shown that…
Threshold expansions of the $\pi\pi$ and $K\overline{K}$ spin 0 and isospin 0 scattering amplitudes are performed. Scattering lengths, effective ranges and so--called volume parameters are evaluated. Good agreement with the existing…
The effects of initial-state Coulomb interactions in the charge-symmetry-breaking reaction dd -> alpha pi^0 are investigated within a previously published formalism. This is a leading order effect in which the Coulomb interaction between…
The construction of the complete isospin relations and inequalities between the possible charge configurations of a $\tau\to K\bar Kn\pi\nu$ decay mode is presented. Detailed applications to the cases of two and three pions are given.
The OKA Collaboration has obtained a new upper limit on the $K^+ \to \pi^0\pi^0\pi^0 e^+ \nu$ decay probability which is 65 times lower than the one currently listed by PDG. However it is still about $10^{4}$ times worse than the…
The decays $\bar{B}\to \bar{K}D$ and $\bar{B}\to \bar{K}\bar{D}$ taking into account final state interactions are discussed. These decays are described by four strong phases $\delta_0, \delta_1, \tilde{\delta}_0, \tilde{\delta}_1$…
Coulomb and mass difference corrections to low-energy pion-nucleon scattering are calculated and compared with previous work including potential models, dispersion relation methods and chiral perturbation theory calculations. Particular…